Answers:
x = 16
MB = 31
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Work Shown:
M is the midpoint of AB
This means AM is half as long as AB and AM = MB
Put another way, AB is twice as long as AM
AB = 2*AM
3x+14 = 2*(2x-1)
3x+14 = 4x-2
14+2 = 4x-3x
16 = x
x = 16
AM = MB
MB = AM
MB = 2x-1
MB = 2*16-1
MB = 32-1
MB = 31